Sample holders (SH) are devices used to support specimens to be analyzed by SEM and/or AFM and other microscopy techniques. Each of which uses SHs with very particular designs due to their characteristics and specific functionalities [1, 2], such that there is a wide variety of SHs, which not only hold the specimen but also add position, grip, sample size, sample shape, tilting and even confining pressure features. However, none of the existing SH allows studying the same sample in both SEM and AFM, maintaining the sample-features in the same positioning reference. This advantageous feature of keeping the same positioning reference in both microscopy techniques is essential to obtain relevant and complementary information within the correlational microscopy field [3].
Table No. 1 Presents the SHs more closely related to the present invention device features, existing in the market.
TABLE No. 1SHs for SEM existing in the market, more closely related to the present invention device functionality. DeviceDevice features ObservationsFIG. SH for irregular samples such as rock-Designed to hold No. 1 fragments and other abnormal shapesand insert (polymers, metals, etcetera) irregularly (http://www.emsdiasum.com/microscopy/shaped products/sem/holder.aspx). specimens; not suited for fragile and thin samples.FIG. Holder for SH tailored for Hitachi ®Too big to be No. 2SEM, designed for both, flat and inserted in an irregular samples AFM stage. (http://www.ultratecusa.com/sem-stub- holders). FIG. SH for metallurgic samples although it It cannot be No. 3may be used to sustain rock fragments, inserted in an polymers and other materials previously AFM. prepared to fit in it. This SH includes a Phillips-type pin underneath and is aluminum made. (http://www.emsdiasum.com/microscopy/products/sem/holder.aspx). FIG. SH for SEM dual beam microscopes,It cannot be No. 4designed to prepare samples oninserted in an transmission electron microscopy AFM stage. (TEM) grids, includes a Phillips-type pin underneath and is aluminum made. (http://www.emsdiasum.com/microscopy/products/sem/holder.aspx). FIG. SH for SEM dual beam microscopes, Even without the No. 5designed to prepare samples on lower pin, it is transmission electron microscopy (TEM) too big to be grids, includes a Phillips-type pin inserted in an underneath and is aluminum made AFM stage. (http://www.emsdiasum.com/microscopy/products/sem/holder.aspx). FIG. SH for up to 7 mm thick flat samples The grip method No. 6used in SEM. It is aluminum made and may damage includes bronze screws and a Phillips- fragile samples type lower pin. and is unable to (http://www.emsdiasum.com/microscopy/hold small products/sem/holder.aspx). specimens such as AFM specimens, besides is not convenient for AFM-SH and is not magnetic. FIG. Conventional SH Phillips-type for SEM, It requires No. 7its dimensions are 12.5 mm, 3.2 mm × double-sided 6.0 mm, aluminum made. tape, and cannot (http://www.agarscientific.com/sem/ be inserted in an specimen-stubs-mounts.html). AFM stage. FIG. SH Phillips-type for SEM with lower It cannot be No. 8pin, tailored for acicular specimens inserted in an such as fibers, wires and up to 17.5 AFM stage. mm long sheets and other. because of its (http://www.efjeld.com/P_S-hold.htm). lower pin, and it is too tall for the stage.FIG. SH designed for thin sheet-like samples The SH cannot No. 9such as paper, metallic films and wires be inserted in an no larger than 25.4 mm. AFM stage (http://www.efjeld.com/P_S-hold.htm). because of its lower pin.
As it can be seen from Table No. 1, The SEM-designed SHs can be so simple and practical or have a very sophisticated design, providing additional capabilities to support a sample. However, as far as the authors is concerned, none of the existing SHs allows to study the same sample in the same region in both SEM and AFM for the following reasons:                a) They are not designed to keep the same positioning reference when changing from SEM to AFM.        b) Their physical support can damage fragile samples.        c) They are too big to fit into the AFM stage.        d) Many of them require the use of electrons-conducting double sided tape to maintain the specimen in place, which is not acceptable in AFM imaging since the samples can become contaminated with the adhesive on the tape and introduce unexpected damping behavior during both, tapping or continuous imaging and micromechanical testing in AFM [4].        